Long ago, in the depths of space, two races of intelligent beings went to war with the goal of complete annihilation of each other—eventually creating an absolute weapon that ended the conflict. These are killing machines with computer minds that continue their program of destruction, moving through the Galaxy and erasing everything alive in their path. Now their course is set toward the borders of space inhabited by humans. Humans named them berserkers, and, having proven themselves skilled in wars, they accepted the challenge. A century after defeating the berserker fleet, humanity grew accustomed to peace and lost vigilance. But the killing machines have restored themselves and are ready to attack again, threatening to wipe out humankind. The only thing that can stop them is a child who is half machine itself.